title: External quality assessment of automated blood leukocyte differential counts and other simultaneous measured quantities.
abstract: An external quality assessment scheme (EQAS) of automated differential counts of leukocytes has been carried out using selected fresh blood specimens. The measurements were carried out one day after blood drawing because of the delay in the mail. Reference laboratories established target values for differential counts. They counted visually 600-700 cells in each specimen on smears. The consensus value among 12 laboratories for manual count of total leukocytes was used as target value, but was found on average 9% smaller than the average instrumental value. H1 results compared favorable with the target value for the differentials. The less advantageous findings on Coulter S + IV are partly explained by the age of the specimen when measured. The data indicated that better calibration of the instruments could decrease the overall variation of platelets counts and haemoglobin determinations. An EQAS involving measurement on fresh specimens is in progress.
authors.affiliation: University of Copenhagen, Department of Clinical Chemistry, Herlev Hospital, Denmark.
authors.forename: A
authors.initials: A
authors.lastname: Uldall
authors.forename: L
authors.initials: L
authors.lastname: Jacobsson
authors.forename: A
authors.initials: A
authors.lastname: Rajamäki
mesh_terms: D001793:Blood Preservation; D001800:Blood Specimen Collection; D006400:Hematocrit; D006454:Hemoglobins / Q000032:analysis; D006801:Humans; D007958:Leukocyte Count / Q000295:instrumentation*; D011786:Quality Control; D012015:Reference Standards; D013696:Temperature
chemical_list: D006454:Hemoglobins